Typically, redundant data processing is utilized in safety-related applications or in environments that are susceptible to malfunctioning (prone to breakdown), that is if either a high standard is placed to reliability of a result of a processing step or if failures or malfunctions cannot be avoided or are to be expected due to the operation environment.
Electronic circuits, in particular circuits that are built up at least in part with semiconductor elements, may be exposed to radiation under conditions in outer space out of the earth's atmosphere, which radiation may result in undesired behavior or malfunction of the semiconductor elements. In particular, it may happen that under the influence of such radiation the behavior of the semiconductor elements may deviate or differ from a functional or expected behavior.
Digital electronic circuits that are designed in a redundant manner for the purpose of suppressing radiation-related malfunctions must typically resolve the redundancy at their output interfaces. So-called output buffers are used for this purpose. Here, the output buffers may be a residual sensitive part as these, in turn, may be susceptible to malfunctioning or may have an impact on voltage drops and/or drive strength losses (drop of the current provided at the output interface).
In particular, the output buffer may be a tristate output buffer, which means that it may take the three logical values “1”, “0”, “high impedance” at its output interface.